AngularJS as powerful as it is doesn't really have a lot utility methods and this is where underscore comes in. Underscore provides 80-odd functions that support both the usual functional suspects: map, select, invoke — as well as more specialized helpers.
To get the most of underscore with AngularJS, you have to "provide" underscore into AngularJS via a factory method:
var myapp= angular.module('underscore', []);
myapp.factory('_', function() {
return window._; // underscore has been loaded before this script
});
With that, we can now inject underscore into our controllers:
myapp.controller("SomeCtrl",[$scope, _, function($scope, _){
$scope.maxVal = _.max([1,2,3]); // Returns 3
});
Which leads to a couple of pretty handy stuff like checking for undefined values:
myapp.controller("SomeCtrl",[$scope, _, function($scope, _){
if(_.isUndefined($scope.someValue){
// do something because someValue is undefined
}
});
Or do a search over some array using some attribute without resorting to a loop.
myapp.controller("SomeCtrl",[$scope, _, function($scope, _){
var data = [{model:"T", manufacturer: "Nokia"},
{model:"S", manufacturer:"Samsung"},
{model:"r8", manufacturer:"Cherry Mobile"},
{model:"One", manufacturer:"HTC"}];
//Code to fetch a Cherry Mobile phone
var phone = _.where(data, {manufacturer: "Cherry Mobile"});
// phone should be [{model:"r8", manufacturer:"Cherry Mobile"}]
});
By combining these awesome frameworks, you're setting up yourself to dish out some serious can of whoop ass.
